FLEMINGER: INTEGUMENTAL ORGANS IN GENUS EUCALANUS 



Table 6. — Total number (PN) of perforations in samples of Eucalamis subtemtis from different oceans. 



Sample 



Range 



N 



Pacific Ocean 

 Indian Ocean 

 Atlantic Ocean 



114-135 

 119-139 

 125-141 



123.6388 

 130.0416 

 134.8400 



4.9750 

 4.991 1 

 3.2598 



24.7506 

 24.911 1 

 10.6263 



36 

 24 

 50 



Comparison of differences between mean number (Student's t - test) 



Pacific : Indian 60 4.877 <0.001 



Indian : Atlantic 74 4.98 <0.001 



Atlantic : Indian-Pacific combined 1 10 9.37 <0.001 



position to those of the Pacific and Atlantic 

 populations, a pattern consistent with the pre- 

 vailing surface circulations of equatorial and 

 western boundary currents. 



When the various sets of perforations are 

 analyzed separately, however, the resemblance 

 of the variation to either a zone of intergrada- 

 tion or a stepped cline disappears. The designat- 



ed sites in E. subtenuis fall into 26 tergal and 

 13 pleural sets based on the scheme described 

 above (Figures 5, 7). More than half of these 

 sets show zero or negligible variability, i.e., 

 typical perforations were observed at these 

 sites in virtually all of the specimens. Most of 

 the variation was in fact concentrated in only 

 nine sets of designated sites (Figure 22a, b). 



a 



u 



140 



► 

 135 



-£r^ 



g 130 



125 



120 



a 



h 



90PW-30°W 

 Atlantic 



1151- 



_L 



30°W-30°E 



J I I 



3 



^ 



^ 



3 



30°E-90°E 



J I 



sm 



90°E-150°E 



J I I 



150°W-90°(70°)W 

 Pacific 



O 



6 



CI2460246024602460246 



Frequency 



Figure 21. — Frequency distribution of total number (PN) of perforations per specimen in samples of adult females of 

 Eucalanus subtenuis collected within 60° segments of longitude. Uniform large spot shading represents specimens collected 

 at localities in the Atlantic Ocean; obliquely ruled shading represents specimens collected at localities in the Indian Ocean; 

 irregular finely dotted shading represents specimens collected at localities in the Pacific Ocean. Differences between the 

 means in the second and third histograms and the fourth and fifth histograms counting from the left are highly signifiicant 

 ((-test. Table 7). Black triangle indicates position of mean PN within geographical segment. All specimens selected at ran- 

 dom from zooplankton samples located in various sectors of the suhicnuis range (Figure 20). 



1001 



